Or personal scoring and coloured thread titles to suit. This isn't about the HN ranking mechanism, it's about finding and highlights article titles that might be interesting to the user.
In my case it really is about filtering, though, rather than discovery.
I like seeing things I wouldn't specifically choose to see, but I know if it has 'bitcoin', 'snowden' or 'CIA' in it, it's almost never going to appeal to me.
But yeah, if it was generic enough, such a thing could be used to highlight or hide, appealing to both approaches.
Or personal scoring and coloured thread titles to suit. This isn't about the HN ranking mechanism, it's about finding and highlights article titles that might be interesting to the user.